A 238-foot ocean research vessel from Massachusetts sailed across the Great Lakes into Duluth this week to begin a unique scientific mission to detect neutrinos — tiny, subatomic particles that may hold the secret to the beginning of the universe.

Neutrinos are sometimes called "ghost particles" because they're extremely difficult to detect. They rarely interact with matter and they pass through most materials without leaving a trace. They’re also, literally, almost everywhere.

"There are a billion of them for every normal electron or proton that you're used to. So, the most numerous particle in the universe, and we know the least about them,” explained Alec Habig, a physics professor at the University of Minnesota Duluth who is the lead investigator on the project.

The Experimental Neutrino Detector project, as it’s called, is the latest in a long legacy of neutrino research in Minnesota. It’s designed to detect neutrinos 200 meters below the surface of Lake Superior, and it will mark the first time ever that neutrino detectors will be deployed in a freshwater lake.

Since 2005, the U.S. Department of Energy’s Fermi National Accelerator Laboratory outside of Chicago, known as Fermilab, has generated the world's strongest neutrino beam with a particle accelerator. That beam is aimed underground toward northern Minnesota.

For years there was a neutrino director located deep in the Soudan Underground Mine near Ely. Now, a lab in Ash River just outside Voyageurs National Park detects neutrinos from Fermilab. But that beam is scheduled to shut off in February because scientists have built a newer one.

"That beam goes right under Wisconsin and eclipses Lake Superior off of Two Harbors on its way to the labs up north,” said Habig. “The chance to see what happens in Lake Superior as the beam goes through it — this is why we're here."

For the experiment, crews have built five giant frames. Each one is about three stories tall and weighs about 8,000 pounds, and each frame holds 18 spherical sensors that are about the size of a beach ball and filled with photo tubes.

When neutrinos travel through the water, they emit faint flashes of blue light when they occasionally collide with atoms. During the night, the photo tubes can detect those flashes. The system is designed to differentiate neutrinos in the beam from neutrinos generated by the sun and other natural sources.

"We can connect the dots and see it went from here to here and tell that it's coming from the direction of Fermilab and not other cosmic radiation coming down from above,” Habig said.

The University of Minnesota Duluth is leading the project, in cooperation with the U.S. Department of Energy and two national labs. It's sponsored by the Defense Advanced Research Projects Agency, or DARPA.

Project leaders didn’t know the total cost but said it is in the tens of millions of dollars.

Some reports suggest the research could eventually be used to track nuclear submarines or find secret nuclear reactors by detecting the neutrinos emitted by those facilities.

John Bruzzese, a program manager for DARPA, says the agency doesn't have a specific application in mind for this project. Neutrinos, he said, remind him of the discovery of X-rays, which also pass through matter.

"When we discovered those, we could not imagine what the applications would be,” Bruzzese said. “Now we see this is part of daily life. Here with neutrinos, we don't know what the future is. It's DARPA's role to continue monitoring, funding research, so that when we understand, we can prepare our nation for that new world."

The research vessel is called the Neil Armstrong and comes from the Woods Hole Oceanographic Institution. On Thursday, it will cruise to a spot about 3 miles out into the lake from Two Harbors, where it will use a crane to start lowering the sensors into place on the lakebed. Crews will then lay fiber optic cables to connect them to a temporary facility on shore near Two Harbors.

At the end of the experiment, the underwater sensors will be retrieved and sent to Europe, where they will be used in neutrino research deep in the Mediterranean Sea.

Researchers don't really know yet what they'll learn from the neutrinos. UMD's Habig says this project may not make a great discovery. But it will lay the groundwork for future neutrino detectors. “How does it work? What challenges are there? Can we do it?” he said.

And those discoveries may help answer much larger questions, said Rob Munier, Vice President for Marine Facilities and Operations at the Woods Hole Oceanographic Institution.

"What we're doing here at the bottom of Lake Superior is nothing less than the exploration of the cosmos,” Munier said, “to help answer the question: Why do we live in a matter-dominated universe? Or put more simply, why are we here?"

Collected from Minnesota Public Radio News. View original source here.